With medical instruments, there often exists the need to releasably connect instrument parts to one another in a gas-tight and fluid-tight manner. One example of this is endoscopic shank instruments, with which an exchangeable working insert which is led through the shank of the instrument is fixed at the proximal end of the shank in a gas-tight or fluid-tight manner.
Cone connections, which are secured from unintended release by way of positive-fit means, are particularly suitable for creating a gas-tight or fluid-tight connection of such instrument parts. In this context, it is known to lock the cone connection by way of a bayonet closure, wherein an end section of a second instrument part which corresponds to the receiving space of the first instrument part is inserted into this conically designed receiving space, and the two instrument parts are positively and non-positively connected to one another with an externally attached clamping ring forming part of the bayonet closure. The creation of the connection of the two instrument parts is comparatively uncomfortable since the clamping ring must be brought into a prescribed position by way of a suitable rotation, before the connection of the two instrument parts as well as for the release of the connection.